The invention relates more particularly to a heating device, particularly for heating preforms made of thermoplastic material, having:                a lamp having a tubular bulb, the lamp having two free end segments, each of which has an end stem of the bulb and an end base that is secured to the stem;        at least one reflector that extends longitudinally at a set transverse distance from the tubular bulb;        two elements for holding the lamp in transverse position relative to the reflector, each holding element being secured to the reflector.        
It is known to manufacture containers made of thermoplastic material by forming preforms, for example by blow molding or by stretch blow molding. To perform the forming operation, it is necessary to heat in advance the body of the preforms to a glass transition temperature to make it malleable. The installations for mass production of containers have for this purpose stations for heating the preforms.
A heating station generally has the shape of a tunnel in which at least one of the walls is formed by an assembly of several heating modules equipped with heating devices of the type described previously. The preforms advance along the tunnel in front of the heating modules while rotating around themselves so that their bodies are heated uniformly to a temperature suitable for the forming operation.
The lamps used for the heating of the preforms are generally halogen-type lamps that emit a heating electromagnetic radiation, for example an infrared radiation. They have a bulb of which a tubular part encloses a filament that extends longitudinally between two bases. Each base makes possible the supply of electricity to the filament. When it is supplied with adequate electrical power, the filament emits the heating radiation radially in all directions.
Such a tube-shaped lamp diffuses the heating electromagnetic radiation in all directions. Thus, a portion of the radiation is not directed toward the preform. Consequently, to heat a preform, a portion of the electrical energy is consumed by the lamp to no purpose.
To make possible a substantial savings in energy, it is known to arrange a reflector near the tubular bulb to send the light radiation back toward the preform. Such a reflector is made of a material that is resistant to the high heat produced by the lamp, for example made of ceramic.
Currently, the reflectors are permanently secured to the lamp. Consequently, in the event the lamp fails, the entire heating device formed by the lamp and the reflector must be replaced.